Surprise effects of wolves in Yellowstone

I was just at Yellowstone and have been reading the nps articles before and after the trip about the wolves. While talking to the locals it was interesting how thier take on them is completely opposite of what I read. They were mostly all against them and the park thinks it's the greatest thing since sliced bread. I guess though if we killed them off they should be brought back in effort to make like it once was. Unless you live there.